Two straight seasons of NFL ratings declines have left some observers of the media marketplace wondering if Super Bowl LII may fail to measure up to the sort of dizzying deliveries that, in recent years, have become all but preordained. Luckily for NBC and the advertisers that have ponied up the big bucks for a shot at reaching the year's largest TV audience, there is no demonstrable correlation between regular-season and playoff ratings and America's enthusiasm for the Big Game.

In a note to investors, MoffettNathanson analyst Michael Nathanson on Monday kicked off his comprehensive examination of the NFL's vital signs with a jarring hypothetical. "Will this Sunday's Super Bowl be watched by 13 percent fewer viewers?" Nathanson wrote. "If this past season and playoffs serve as a guide, odds are that more Americans will tune the game out than last year. And that's not because we are tired of watching the Patriots."

While it's impossible to discount Brady Fatigue altogether—unless you exclusively refer to that big coffee chain as "Dunks" or "Dunkies" and regularly deploy the phrase "wicked pissah" to express your satisfaction with the state of things, you're probably sick to death of the Pats—nothing short of a nuclear strike is likely to drive NBC's Super Bowl deliveries south of the 108 million-viewer mark. Regardless of the matchup or the quality of play, not to mention general downward trends in traditional TV viewing, the Super Bowl is the only TV program for which the ratings are high enough to trigger altitude sickness. And so far, they're staying that way.

The Only Game in Town

Super Bowl Ratings Up 33% Since 2001

Since 2010, when CBS first crashed through the 100 million viewer barrier with its coverage of Super Bowl XLIV, the big game has never so much as flirted with an average delivery below that. In fact, six of the seven NFL title tilts that aired after that Colts-Saints showdown have averaged more than 110 million viewers; only the 2013 Super Bowl dipped below that number, and the 2 percent dip had almost everything to do with the fact that the Ravens had a commanding 28-6 second-half lead over the 49ers when a 34-minute power outage left CBS scrambling to impose order down in New Orleans.

As you'll see at a mere glance at the charts, the Super Bowl not only eclipses everything else on primetime TV, but it is a remarkably consistent reach vehicle. Whereas the ratings readout for the volatile AFC and NFC Championship Games looks like the EKG of someone who's being chased by a peckish bear, the year-to-year shifts in Super Bowl deliveries show very little deviation from the zero. Aside from the breakout year that was 2010, when ratings jumped 8 percent, the red Super Bowl line looks like a gentle sine wave.

By comparison, the annual rate-of-change for regular-season NFL ratings are all over the map. And as the second graph demonstrates, there is no reciprocity between the turnout for the Super Bowl and how that season's broadcast prime numbers stack up. In other words, there's not much of a case to be made for trying to predict the final Super Bowl deliveries based on an analysis of everything else on TV. The Super Bowl is sui generis, and perhaps because it has become a centerpiece of America's other great secular holiday or because half of the people who tune in on Super Sunday claim they do so in order to check out the ads, the game appears impervious to the maladies that continue to erode the ratings during the other 364 days of the year.

On the very unlikely chance the Nathanson's hypothetical proves to be prescient and Super Bowl LII suffers the same 9 percent drop the NFL experienced in the regular season, the average deliveries will still approach 102 million overall viewers. Ultimately, the stakes aren't particularly high for NBC; as with fellow rights holders CBS and Fox, the Peacock doesn't offer ratings guarantees to its Super Bowl advertisers, so there's no danger of it being on the hook for make-goods. When it comes right down to it, Super Bowl ratings are primarily about bragging rights. If anything, they're somewhat useful in establishing a baseline unit cost for the next network in line to host the game.

(A procedural note: Broadcast prime ratings reflect the overall deliveries for ABC, CBS, NBC and Fox in the 17 or 18 weeks of the season that overlap with the NFL schedule. All ratings are derived from Nielsen live-plus-same-day data.)